Production of Dirhams at the Mint of Damascus (Dimashq) in the First Four Centuries of Islam and the Question of Near Eastern Metallic Zones

All examination of 159 hoards with 1822 dirhams minted at Damascus during the first four centuries of Islam sheds much light on a number of important questions regarding the economic history of the Near East during the Umayyad, 'Abbasid, and Ikhshidid eras. Using the hoard-count method of estimating mint outputs, it has been determined that the Damascus mint was significantly active only during the Umayyad period, a time when the city was the capital of the caliphate. Having no local silver mines and lacking revenue transfers from the provinces after 127 H, Damascus was, at best, a marginal mint for the production of dirhams. However, because Syria and the eastern Mediterranean region in general fell into a gold-copper metallic zone during the period in question, it is surprising that Damascus was at all an important mint when the city was the capital of the Islamic world

Dirham Mint Output of Samanid Samarqand and its Connection to the Beginnings of Trade with Northern Europe (10th century)

La production de dirhams de l’atelier samanide de Samarkand et les débuts du commerce vers l’Europe du Nord (xe siècle).L’examen des 14 865 dirhams samanides des xe et xie siècles frappés à Samarkand provenant de 634 trésors découverts en Eurasie occidentale montre que ces monnaies étaient principalement destinées au commerce avec l’Europe du Nord. Samarkand fut l’atelier principal émettant des dirhams pendant la majeure partie du ixe et du xe siècle, mais sa période d’activité la plus intense dura depuis les années 910 jusqu’au milieu des années 920. Ainsi, avant 954, 92,26% de l’ensemble des monnaies émises à Samarkand avaient-elles déjà été frappées. Les débuts de la production des dirhams à Samarkand au début des années 890 et la forte augmentation durant les deux décennies qui suivirent correspondent à la phase de croissance du commerce entre l’Europe du Nord et le Caucase qui débuta vers 900. La baisse catastrophique de la production monétaire à partir de la seconde moitié du xe siècle peut être attribuée au déclin général de l’économie samanide qui s’amorça dans les années 940.An examination of 14,865 Samanid dirhams struck in Samarqand from 634 hoards discovered in western Eurasia dating from the tenth to the eleventh centuries shows that these coins were destined mainly for trade with northern Europe. Samarqand was a primary Samanid mint that issued dirhams during most of late ninth and tenth centuries, but its most intense years of production occurred from the 910s to the mid-920s. By 954, 92.26% of all dirhams issued in Samarqand by the Samanids had been struck. The beginnings of dirham production in Samarqand in the early 890s and the sharp increase in production in the following two decades closely correspond with the rise of commerce between northern Europe and Central Asia which initiated in ca. 900. The catastrophic drop in mint output from the second half of the tenth century can be attributed to the general decline in the Samanid economy that began with the fifth decade of the same century

Measurement of the mass difference m(D-s(+))-m(D+) at CDF II

We present a measurement of the mass difference m(D-s(+))-m(D+), where both the D-s(+) and D+ are reconstructed in the phipi(+) decay channel. This measurement uses 11.6 pb(-1) of data collected by CDF II using the new displaced-track trigger. The mass difference is found to be m(D-s(+))-m(D+)=99.41+/-0.38(stat)+/-0.21(syst) MeV/c(2)

Polarimetric Properties of Event Horizon Telescope Targets from ALMA

We present the results from a full polarization study carried out with the Atacama Large Millimeter/submillimeter Array (ALMA) during the first Very Long Baseline Interferometry (VLBI) campaign, which was conducted in 2017 April in the λ3 mm and λ1.3 mm bands, in concert with the Global mm-VLBI Array (GMVA) and the Event Horizon Telescope (EHT), respectively. We determine the polarization and Faraday properties of all VLBI targets, including Sgr A*, M87, and a dozen radio-loud active galactic nuclei (AGNs), in the two bands at several epochs in a time window of 10 days. We detect high linear polarization fractions (2%–15%) and large rotation measures (RM > 103.3–105.5 rad m−2), confirming the trends of previous AGN studies at millimeter wavelengths. We find that blazars are more strongly polarized than other AGNs in the sample, while exhibiting (on average) order-of-magnitude lower RM values, consistent with the AGN viewing angle unification scheme. For Sgr A* we report a mean RM of (−4.2 ± 0.3) × 105 rad m−2 at 1.3 mm, consistent with measurements over the past decade and, for the first time, an RM of (–2.1 ± 0.1) × 105 rad m−2 at 3 mm, suggesting that about half of the Faraday rotation at 1.3 mm may occur between the 3 mm photosphere and the 1.3 mm source. We also report the first unambiguous measurement of RM toward the M87 nucleus at millimeter wavelengths, which undergoes significant changes in magnitude and sign reversals on a one year timescale, spanning the range from −1.2 to 0.3 × 105 rad m−2 at 3 mm and −4.1 to 1.5 × 105 rad m−2 at 1.3 mm. Given this time variability, we argue that, unlike the case of Sgr A*, the RM in M87 does not provide an accurate estimate of the mass accretion rate onto the black hole. We put forward a two-component model, comprised of a variable compact region and a static extended region, that can simultaneously explain the polarimetric properties observed by both the EHT (on horizon scales) and ALMA (which observes the combined emission from both components). These measurements provide critical constraints for the calibration, analysis, and interpretation of simultaneously obtained VLBI data with the EHT and GMVA

Rus mercenaries in the Byzantine-Arab wars of the 950s-960s: the numismatic evidence

Using specific coin types (tenth-century dirhams and pre-970 Byzantine miliaresia) imported from the eastern Mediterranean and upper Mesopotamia in a very restricted chronological period (950s-960s) through (the Dnepr River) and into a confined region of the Northern lands (mainly Sweden) – combined with the evidence of Arab, Byzantine, and Rus’ written sources – this study argues that it is possible to trace numismatically the participation of Rus’ mercenaries in the Byzantine-Arab wars of the late 950s-960s. While dirhams discovered in the Northern lands are most commonly associated with trade relations between the Islamic world and Viking-age Northern Europe, the coins considered in this study offer a unique opportunity to identify and examine some of the non-commercial origins of silver imported into the region: they were products of loot and payments, generated by the Rus’ from their military operations in the eastern Mediterranean basin in the 950s-960s

Thomas S. Noonan in memoriam

Kovalev Roman K., Rispling Gert. Thomas S. Noonan in memoriam. In: Revue numismatique, 6e série - Tome 158, année 2002 pp. 375-383

Assembling the Puzzle of Taxifolin Polymorphism

A large amount of the current literature dedicated to solid states of active pharmaceutical ingredients (APIs) pays special attention to polymorphism of flavonoids. Taxifolin (also known as dihydroquercetin) is an example of a typical flavonoid. Some new forms of taxifolin have been reported previously, however it is still unclear whether they represent polymorphic modifications. In this paper, we tried to answer the question about the taxifolin polymorphism. Taxifolin microtubes and taxifolin microspheres were synthesized from raw taxifolin API using several methods of crystal engineering. All forms were described with the help of spectral methods, scanning electron microscopy (SEM), X-ray powder diffraction (XRPD), and thermal analysis (TA). SEM reveals that the morphology of the solid phase is very specific for each sample. Although XRPD patterns of raw taxifolin and microtubes look similar, their TA profiles differ significantly. At the same time, raw taxifolin and microspheres have nearly identical thermograms, while XRPD shows that the former is a crystalline and the latter is an amorphous substance. Only the use of complex analyses allowed us to put the puzzle together and to confirm the polymorphism of taxifolin. This article demonstrates that taxifolin microtubes are a pseudopolymorphic modification of raw taxifolin